Processing measurement data that involves computing a derivative of the measurement data that represents a subterranean structure

Abstract

To process measurement data representing a subterranean structure, a derivative of the measurement data collected by at least one survey receiver is computed, with respect to frequency. A response representing the subterranean structure is then computed based on the derivative of the measurement data, where the response contains an air-wave component that has been suppressed due to computing the derivative of the measurement data relative to at least another component that is sensitive to the subterranean structure.

1. A method of processing measurement data representing a subterranean structure, comprising:
 receiving the measurement data collected by at least one survey receiver; 
 computing a derivative of the measurement data with respect to frequency; and 
 computing a response representing the subterranean structure based on the derivative of the measurement data, wherein the response contains a particular component that has been suppressed due to computing the derivative of the measurement data relative to at least another component that is sensitive to the subterranean structure. 
 
     
     
       2. The method of  claim 1 , wherein receiving the measurement data comprises receiving electric field data, and wherein computing the derivative comprises computing the derivative of the electric field data. 
     
     
       3. The method of  claim 1 , wherein receiving the measurement data comprises receiving magnetic field data, and wherein computing the derivative comprises computing the derivative of the magnetic field data. 
     
     
       4. The method of  claim 1 , wherein computing the derivative comprises computing the derivative of function applied to the measurement data. 
     
     
       5. The method of  claim 1 , wherein receiving the measurement data comprises receiving the measurement data collected by at least one electromagnetic receiver. 
     
     
       6. The method of  claim 1 , wherein receiving the measurement data collected by the at least one survey receiver comprises receiving the measurement data collected by the at least one survey receiver in a marine survey arrangement. 
     
     
       7. The method of  claim 1 , wherein receiving the measurement data collected by the at least one survey receiver is in a deepwater marine survey arrangement. 
     
     
       8. The method of  claim 1 , wherein receiving the measurement data collected by the at least one survey receiver comprises receiving the measurement data collected by the at least one survey receiver in a land-based survey arrangement. 
     
     
       9. The method of  claim 8 , wherein receiving the measurement data collected by the at least one survey receiver is in a shallow water marine survey arrangement. 
     
     
       10. The method of  claim 1 , wherein the particular component that has been suppressed comprises an air-wave signal component. 
     
     
       11. The method of  claim 10 , wherein computing the derivative causes the air-wave signal component to be suppressed with respect to an original version of the air-wave signal component prior to computing the derivative. 
     
     
       12. The method of  claim 10 , wherein computing the derivative causes the at least another component that is sensitive to the subterranean structure to be enhanced with respect to an original version of the at least another component prior to computing the derivative. 
     
     
       13. The method of  claim 10 , wherein the at least another component comprises a direct-wave response and a modified-image response. 
     
     
       14. The method of  claim 10 , wherein computing the derivative causes the at least another component that is sensitive to the subterranean structure to be enhanced by a first factor with respect to an original version of the at least another component prior to computing the derivative, and causes the air-wave signal component to be enhanced by a second factor with respect to an original version of the air-wave signal component prior to computing the derivative,
 wherein the first factor is greater than the second factor. 
 
     
     
       15. An article comprising at least one computer-readable storage medium containing instructions that when executed cause a computer to:
 receive measurement data collected by at least one electromagnetic receiver; 
 compute a derivative of the measurement data with respect to frequency; and 
 compute a response representing the subterranean structure based on the derivative of the measurement data, wherein the response contains an air-wave signal component that has been suppressed due to computing the derivative of the measurement data relative to at least another signal component that is sensitive to the subterranean structure. 
 
     
     
       16. The article of  claim 15 , wherein computing the derivative causes the air-wave signal component to be suppressed with respect to an original version of the air-wave signal component prior to computing the derivative. 
     
     
       17. The article of  claim 16 , wherein computing the derivative causes the at least another signal component that is sensitive to the subterranean structure to be enhanced with respect to an original version of the at least another signal component prior to computing the derivative. 
     
     
       18. The article of  claim 17 , wherein the at least another signal component comprises a direct-wave response and a modified-image response. 
     
     
       19. A computer comprising:
 a processor; and 
 processing software executable on the processor to:
 receive measurement data collected by at least one survey receiver; 
 compute a derivative of the measurement data with respect to frequency; and 
 compute a response representing the subterranean structure based on the derivative of the measurement data, wherein the response contains an air-wave component that has been suppressed due to computing the derivative of the measurement data relative to at least another component that is sensitive to the subterranean structure. 
 
 
     
     
       20. The computer of  claim 19 , wherein the measurement data comprises measurement data collected by at least one electromagnetic receiver.